1. Field of the Invention
The present invention deals with lighting systems. More particularly, the present invention deals with lighting systems known in the art as track lighting systems. Most particularly, the present invention deals with an improved track lighting system, and an improved lighting truss for use therein.
2. Description of the Prior Art
Track lighting systems for providing illumination of displays in retail and other establishments are well known. Such lighting tracks not only provide an electrical connection to a light fixture, but through adaptors mounted to the light fixtures, actually provide the support function as well. One such known lighting track system is the TEK Surface Mount Lighting System from Nokia Aluminum of P.O. Box 117, FIN-02401, Kirkkonummi, Finland.
Lighting tracks may be surface mounted using fasteners such as screw mounts or ceiling clamps, suspended using a suspension wire or suspended rod and tube, or utilize a recessed mounting. An end feed supplies electrical current to the track, with the track body usually serving as ground, and with various arrangements of live and neutral wires contained within the track which provide an electrical connection to the lighting fixture through the track adaptor.
Such track lighting systems generally work well in most instances, but problems arise in applications where a large amount of light is needed relative to the square foot area of the retail establishment. These problems occur because of a combination of factors, most notably the design of track lighting fixtures, which are fed power normally from their end or center, and the manner in which electrical codes rate the total amount of power permitted in a store, and the track.
Generally, electrical codes, although they vary throughout the country, will require rating a track lighting system at a given amount of watts per lineal foot of track. A common number is 90-watts per lineal foot. Since track lighting systems, by their design, are either fed from their end or center, quite some length of track may be necessary to place the track in a position where lighting is desired, and to provide the necessary flexibility. Since each foot of track that is placed in the store will be rated at 90-watts per foot, if the retail store is of the type which requires a lot of track to achieve the necessary lighting, a rating of a large number of watts is quite possible.
However, this large wattage rating causes a problem with another portion of the electrical codes, which only allows a retail establishment to have a certain number of watts per square foot for all lighting requirements. Again, the number of watts per square feet of establishment varies, but a common number is 3-watts per square foot, and this 3-watts per square foot number includes all lighting. It can be understood by those skilled in the art that the more wattage that is put into track lighting, the less wattage can be put into other lighting equipment. Thus, those skilled in the art have continued to search for a solution to the problem of how to put enough light into a high-light requirement store without running afoul of other portions of the electrical code.